Greetings Joe..If it is truly fruit flies, I've had the same problem... do this:
get a small clear cup or glass, fill it with about one inch of Apple Cider Vinegar. To this add about 2-3 drops of Liquid dish soap and stir.
Sit this out where the flies are. The next morning there should be dead flies in it. I change the mixture daily. Works better.
If you try this, let me know how it works for you.